Limonene and linalool hydroperoxi…utine patch testing.

Linalool is a common fragrance ingredient that can break down into irritating compounds called hydroperoxides when exposed to air or light. When researchers patch-tested these oxidized forms on people with dermatitis, they found high rates of allergic reactions—yet linalool hydroperoxides aren't routinely screened in Europe, meaning people with sensitivities might not know they're reacting to this specific ingredient.